Pyrrolizidine Alkaloids from Senecio subulatus and S. glandulosus

Abstract

A new pyrrolizidine alkaloid dihydroretrorsine was isolated from roots of S. subulatus Don ex Hook et Arn var. erectus together with the previously known senecionine and retrorsine. From the roots of S. glandulosus Don ex Hook et Arn was isolated integerrimine and the mixture of the retrorsine and uraramine isomers. The structure of dihydoretrorsine was deduced by spectral and chemicals means.